1. Field of the Invention
The present invention relates to a novel hydrogel copolymer, a substrate coated with the copolymer, a method of producing a microarray using the copolymer, and a microarray produced by the method.
2. Description of the Related Art
In a microarray, certain molecules are immobilized within discrete known regions on a substrate. Examples of such a microarray include polynucleotide and protein microarrays. The microarray is made using a method of sequentially synthesizing a probe material on a substrate or a spotting method in which a previously-synthesized probe material is immobilized on an activated substrate.
In a spotting method, a microarray is made by coating a linker material (e.g. GAPS (gamma-aminopropyltriethoxy silane) and GAPDES (gamma-aminopropyldiethoxy silane), etc.) having a reactive functional group, for example, an amino group, on a substrate and reacting the functional group with a probe material to immobilize the probe material on the substrate, or by coating a linker material on a substrate, activating the linker material, for example, modifying the linker material using N-hydroxysuccinimide (NHS) into a highly reactive material, and reacting the linker material with a probe material having the reactive functional group such as an amino group. Examples of compounds conventionally used as the linker material include an alkylsilane having a carboxylic group and an alkyl sulfur compound having a carboxylic group. These compounds contain silicon or sulfur, and thus can bind to a SiO2 or Au substrate, and have a carboxylic group, and thus can be easily activated.
According to the conventional technology, a linker material can react with a probe material after being coated on a substrate and activated. Thus, reaction efficiency is low and uniform activation cannot be achieved. In addition, a conventional linker material includes a hydrophobic portion such as an alkyl group. Thus, in a method in which signals generated by a reaction between a probe material and a target material on a microarray manufactured using the conventional linker material are measured and analyzed, the analysis efficiency is poor due to a strong signal generated by non-specific binding of the target material to a background portion, i.e., a strong noise.
U.S. Pat. No. 6,174,683 discloses a method of rapidly and inexpensively producing a biochip using a polyurethane-based hydrogel in order to immobilize a probe material on a substrate. Although this method includes the use of hydrogel having polyethyleneoxide (PEO) as a backbone, there is no description regarding high integration of a probe material using poly[N-isopropylacrylamide] of the present invention.
The inventors of the present invention made efforts to solve the problems of the conventional technology and found a compound capable of achieving high integration of a probe material when it is coated on the substrate and being used to produce a microarray.